--- a/src/HOL/List.thy Fri Dec 07 14:30:00 2012 +0100
+++ b/src/HOL/List.thy Fri Dec 07 16:25:33 2012 +0100
@@ -504,7 +504,228 @@
*)
-ML_file "Tools/list_to_set_comprehension.ML"
+ML {*
+(* Simproc for rewriting list comprehensions applied to List.set to set
+ comprehension. *)
+
+signature LIST_TO_SET_COMPREHENSION =
+sig
+ val simproc : simpset -> cterm -> thm option
+end
+
+structure List_to_Set_Comprehension : LIST_TO_SET_COMPREHENSION =
+struct
+
+(* conversion *)
+
+fun all_exists_conv cv ctxt ct =
+ (case Thm.term_of ct of
+ Const (@{const_name HOL.Ex}, _) $ Abs _ =>
+ Conv.arg_conv (Conv.abs_conv (all_exists_conv cv o #2) ctxt) ct
+ | _ => cv ctxt ct)
+
+fun all_but_last_exists_conv cv ctxt ct =
+ (case Thm.term_of ct of
+ Const (@{const_name HOL.Ex}, _) $ Abs (_, _, Const (@{const_name HOL.Ex}, _) $ _) =>
+ Conv.arg_conv (Conv.abs_conv (all_but_last_exists_conv cv o #2) ctxt) ct
+ | _ => cv ctxt ct)
+
+fun Collect_conv cv ctxt ct =
+ (case Thm.term_of ct of
+ Const (@{const_name Set.Collect}, _) $ Abs _ => Conv.arg_conv (Conv.abs_conv cv ctxt) ct
+ | _ => raise CTERM ("Collect_conv", [ct]))
+
+fun Trueprop_conv cv ct =
+ (case Thm.term_of ct of
+ Const (@{const_name Trueprop}, _) $ _ => Conv.arg_conv cv ct
+ | _ => raise CTERM ("Trueprop_conv", [ct]))
+
+fun eq_conv cv1 cv2 ct =
+ (case Thm.term_of ct of
+ Const (@{const_name HOL.eq}, _) $ _ $ _ => Conv.combination_conv (Conv.arg_conv cv1) cv2 ct
+ | _ => raise CTERM ("eq_conv", [ct]))
+
+fun conj_conv cv1 cv2 ct =
+ (case Thm.term_of ct of
+ Const (@{const_name HOL.conj}, _) $ _ $ _ => Conv.combination_conv (Conv.arg_conv cv1) cv2 ct
+ | _ => raise CTERM ("conj_conv", [ct]))
+
+fun rewr_conv' th = Conv.rewr_conv (mk_meta_eq th)
+
+fun conjunct_assoc_conv ct =
+ Conv.try_conv
+ (rewr_conv' @{thm conj_assoc} then_conv conj_conv Conv.all_conv conjunct_assoc_conv) ct
+
+fun right_hand_set_comprehension_conv conv ctxt =
+ Trueprop_conv (eq_conv Conv.all_conv
+ (Collect_conv (all_exists_conv conv o #2) ctxt))
+
+
+(* term abstraction of list comprehension patterns *)
+
+datatype termlets = If | Case of (typ * int)
+
+fun simproc ss redex =
+ let
+ val ctxt = Simplifier.the_context ss
+ val thy = Proof_Context.theory_of ctxt
+ val set_Nil_I = @{thm trans} OF [@{thm set.simps(1)}, @{thm empty_def}]
+ val set_singleton = @{lemma "set [a] = {x. x = a}" by simp}
+ val inst_Collect_mem_eq = @{lemma "set A = {x. x : set A}" by simp}
+ val del_refl_eq = @{lemma "(t = t & P) == P" by simp}
+ fun mk_set T = Const (@{const_name List.set}, HOLogic.listT T --> HOLogic.mk_setT T)
+ fun dest_set (Const (@{const_name List.set}, _) $ xs) = xs
+ fun dest_singleton_list (Const (@{const_name List.Cons}, _)
+ $ t $ (Const (@{const_name List.Nil}, _))) = t
+ | dest_singleton_list t = raise TERM ("dest_singleton_list", [t])
+ (* We check that one case returns a singleton list and all other cases
+ return [], and return the index of the one singleton list case *)
+ fun possible_index_of_singleton_case cases =
+ let
+ fun check (i, case_t) s =
+ (case strip_abs_body case_t of
+ (Const (@{const_name List.Nil}, _)) => s
+ | _ => (case s of NONE => SOME i | SOME _ => NONE))
+ in
+ fold_index check cases NONE
+ end
+ (* returns (case_expr type index chosen_case) option *)
+ fun dest_case case_term =
+ let
+ val (case_const, args) = strip_comb case_term
+ in
+ (case try dest_Const case_const of
+ SOME (c, T) =>
+ (case Datatype.info_of_case thy c of
+ SOME _ =>
+ (case possible_index_of_singleton_case (fst (split_last args)) of
+ SOME i =>
+ let
+ val (Ts, _) = strip_type T
+ val T' = List.last Ts
+ in SOME (List.last args, T', i, nth args i) end
+ | NONE => NONE)
+ | NONE => NONE)
+ | NONE => NONE)
+ end
+ (* returns condition continuing term option *)
+ fun dest_if (Const (@{const_name If}, _) $ cond $ then_t $ Const (@{const_name Nil}, _)) =
+ SOME (cond, then_t)
+ | dest_if _ = NONE
+ fun tac _ [] = rtac set_singleton 1 ORELSE rtac inst_Collect_mem_eq 1
+ | tac ctxt (If :: cont) =
+ Splitter.split_tac [@{thm split_if}] 1
+ THEN rtac @{thm conjI} 1
+ THEN rtac @{thm impI} 1
+ THEN Subgoal.FOCUS (fn {prems, context, ...} =>
+ CONVERSION (right_hand_set_comprehension_conv (K
+ (conj_conv (Conv.rewr_conv (List.last prems RS @{thm Eq_TrueI})) Conv.all_conv
+ then_conv
+ rewr_conv' @{lemma "(True & P) = P" by simp})) context) 1) ctxt 1
+ THEN tac ctxt cont
+ THEN rtac @{thm impI} 1
+ THEN Subgoal.FOCUS (fn {prems, context, ...} =>
+ CONVERSION (right_hand_set_comprehension_conv (K
+ (conj_conv (Conv.rewr_conv (List.last prems RS @{thm Eq_FalseI})) Conv.all_conv
+ then_conv rewr_conv' @{lemma "(False & P) = False" by simp})) context) 1) ctxt 1
+ THEN rtac set_Nil_I 1
+ | tac ctxt (Case (T, i) :: cont) =
+ let
+ val info = Datatype.the_info thy (fst (dest_Type T))
+ in
+ (* do case distinction *)
+ Splitter.split_tac [#split info] 1
+ THEN EVERY (map_index (fn (i', _) =>
+ (if i' < length (#case_rewrites info) - 1 then rtac @{thm conjI} 1 else all_tac)
+ THEN REPEAT_DETERM (rtac @{thm allI} 1)
+ THEN rtac @{thm impI} 1
+ THEN (if i' = i then
+ (* continue recursively *)
+ Subgoal.FOCUS (fn {prems, context, ...} =>
+ CONVERSION (Thm.eta_conversion then_conv right_hand_set_comprehension_conv (K
+ ((conj_conv
+ (eq_conv Conv.all_conv (rewr_conv' (List.last prems)) then_conv
+ (Conv.try_conv (Conv.rewrs_conv (map mk_meta_eq (#inject info)))))
+ Conv.all_conv)
+ then_conv (Conv.try_conv (Conv.rewr_conv del_refl_eq))
+ then_conv conjunct_assoc_conv)) context
+ then_conv (Trueprop_conv (eq_conv Conv.all_conv (Collect_conv (fn (_, ctxt) =>
+ Conv.repeat_conv
+ (all_but_last_exists_conv
+ (K (rewr_conv'
+ @{lemma "(EX x. x = t & P x) = P t" by simp})) ctxt)) context)))) 1) ctxt 1
+ THEN tac ctxt cont
+ else
+ Subgoal.FOCUS (fn {prems, context, ...} =>
+ CONVERSION
+ (right_hand_set_comprehension_conv (K
+ (conj_conv
+ ((eq_conv Conv.all_conv
+ (rewr_conv' (List.last prems))) then_conv
+ (Conv.rewrs_conv (map (fn th => th RS @{thm Eq_FalseI}) (#distinct info))))
+ Conv.all_conv then_conv
+ (rewr_conv' @{lemma "(False & P) = False" by simp}))) context then_conv
+ Trueprop_conv
+ (eq_conv Conv.all_conv
+ (Collect_conv (fn (_, ctxt) =>
+ Conv.repeat_conv
+ (Conv.bottom_conv
+ (K (rewr_conv'
+ @{lemma "(EX x. P) = P" by simp})) ctxt)) context))) 1) ctxt 1
+ THEN rtac set_Nil_I 1)) (#case_rewrites info))
+ end
+ fun make_inner_eqs bound_vs Tis eqs t =
+ (case dest_case t of
+ SOME (x, T, i, cont) =>
+ let
+ val (vs, body) = strip_abs (Pattern.eta_long (map snd bound_vs) cont)
+ val x' = incr_boundvars (length vs) x
+ val eqs' = map (incr_boundvars (length vs)) eqs
+ val (constr_name, _) = nth (the (Datatype.get_constrs thy (fst (dest_Type T)))) i
+ val constr_t =
+ list_comb
+ (Const (constr_name, map snd vs ---> T), map Bound (((length vs) - 1) downto 0))
+ val constr_eq = Const (@{const_name HOL.eq}, T --> T --> @{typ bool}) $ constr_t $ x'
+ in
+ make_inner_eqs (rev vs @ bound_vs) (Case (T, i) :: Tis) (constr_eq :: eqs') body
+ end
+ | NONE =>
+ (case dest_if t of
+ SOME (condition, cont) => make_inner_eqs bound_vs (If :: Tis) (condition :: eqs) cont
+ | NONE =>
+ if eqs = [] then NONE (* no rewriting, nothing to be done *)
+ else
+ let
+ val Type (@{type_name List.list}, [rT]) = fastype_of1 (map snd bound_vs, t)
+ val pat_eq =
+ (case try dest_singleton_list t of
+ SOME t' =>
+ Const (@{const_name HOL.eq}, rT --> rT --> @{typ bool}) $
+ Bound (length bound_vs) $ t'
+ | NONE =>
+ Const (@{const_name Set.member}, rT --> HOLogic.mk_setT rT --> @{typ bool}) $
+ Bound (length bound_vs) $ (mk_set rT $ t))
+ val reverse_bounds = curry subst_bounds
+ ((map Bound ((length bound_vs - 1) downto 0)) @ [Bound (length bound_vs)])
+ val eqs' = map reverse_bounds eqs
+ val pat_eq' = reverse_bounds pat_eq
+ val inner_t =
+ fold (fn (_, T) => fn t => HOLogic.exists_const T $ absdummy T t)
+ (rev bound_vs) (fold (curry HOLogic.mk_conj) eqs' pat_eq')
+ val lhs = term_of redex
+ val rhs = HOLogic.mk_Collect ("x", rT, inner_t)
+ val rewrite_rule_t = HOLogic.mk_Trueprop (HOLogic.mk_eq (lhs, rhs))
+ in
+ SOME
+ ((Goal.prove ctxt [] [] rewrite_rule_t
+ (fn {context, ...} => tac context (rev Tis))) RS @{thm eq_reflection})
+ end))
+ in
+ make_inner_eqs [] [] [] (dest_set (term_of redex))
+ end
+
+end
+*}
simproc_setup list_to_set_comprehension ("set xs") = {* K List_to_Set_Comprehension.simproc *}
@@ -5664,7 +5885,57 @@
subsubsection {* Pretty lists *}
-ML_file "Tools/list_code.ML"
+ML {*
+(* Code generation for list literals. *)
+
+signature LIST_CODE =
+sig
+ val implode_list: string -> string -> Code_Thingol.iterm -> Code_Thingol.iterm list option
+ val default_list: int * string
+ -> (Code_Printer.fixity -> Code_Thingol.iterm -> Pretty.T)
+ -> Code_Printer.fixity -> Code_Thingol.iterm -> Code_Thingol.iterm -> Pretty.T
+ val add_literal_list: string -> theory -> theory
+end;
+
+structure List_Code : LIST_CODE =
+struct
+
+open Basic_Code_Thingol;
+
+fun implode_list nil' cons' t =
+ let
+ fun dest_cons (IConst { name = c, ... } `$ t1 `$ t2) =
+ if c = cons'
+ then SOME (t1, t2)
+ else NONE
+ | dest_cons _ = NONE;
+ val (ts, t') = Code_Thingol.unfoldr dest_cons t;
+ in case t'
+ of IConst { name = c, ... } => if c = nil' then SOME ts else NONE
+ | _ => NONE
+ end;
+
+fun default_list (target_fxy, target_cons) pr fxy t1 t2 =
+ Code_Printer.brackify_infix (target_fxy, Code_Printer.R) fxy (
+ pr (Code_Printer.INFX (target_fxy, Code_Printer.X)) t1,
+ Code_Printer.str target_cons,
+ pr (Code_Printer.INFX (target_fxy, Code_Printer.R)) t2
+ );
+
+fun add_literal_list target =
+ let
+ fun pretty literals [nil', cons'] pr thm vars fxy [(t1, _), (t2, _)] =
+ case Option.map (cons t1) (implode_list nil' cons' t2)
+ of SOME ts =>
+ Code_Printer.literal_list literals (map (pr vars Code_Printer.NOBR) ts)
+ | NONE =>
+ default_list (Code_Printer.infix_cons literals) (pr vars) fxy t1 t2;
+ in Code_Target.add_const_syntax target @{const_name Cons}
+ (SOME (Code_Printer.complex_const_syntax (2, ([@{const_name Nil}, @{const_name Cons}], pretty))))
+ end
+
+end;
+*}
code_type list
(SML "_ list")